diff mbox

[3.0-rc3] i1915: missed IRQ/stalls patch success

Message ID BANLkTimpn8LJwTnH7_GQgb6iL_nwJy+PKA@mail.gmail.com
State New, archived
Headers show

Commit Message

Daniel J Blueman June 14, 2011, 4:18 a.m. UTC
Hi Eric,

The frequent ~1.5s pauses I hit with SNB hardware in the gnome3 UI (eg
whenever you hit the top-left of the screen to show all windows) are
nicely addressed by your recent wake patch [1] (ported to -rc3). Thus
I see no 'missed IRQ' kernel messages.

As this addresses a significant usability regression, are you happy to
add it to the 3.0-rc queue? I think it has very good value in -stable
also (assuming correctness). What do you think?

Thanks,
  Daniel

--- [1] http://lists.freedesktop.org/archives/intel-gfx/2011-June/010863.html


@@ -648,9 +650,11 @@ gen6_ring_put_irq(struct intel_ring_buffer *ring,
u32 gflag, u32 rflag)

 	spin_lock(&ring->irq_lock);
 	if (--ring->irq_refcount == 0) {
+		gen6_gt_force_wake_get(dev_priv);
 		ring->irq_mask |= rflag;
 		I915_WRITE_IMR(ring, ring->irq_mask);
 		ironlake_disable_irq(dev_priv, gflag);
+		gen6_gt_force_wake_put(dev_priv);
 	}
 	spin_unlock(&ring->irq_lock);
 }

Comments

Eric Anholt June 14, 2011, 5:23 a.m. UTC | #1
On Tue, 14 Jun 2011 12:18:36 +0800, Daniel J Blueman <daniel.blueman@gmail.com> wrote:
> Hi Eric,
> 
> The frequent ~1.5s pauses I hit with SNB hardware in the gnome3 UI (eg
> whenever you hit the top-left of the screen to show all windows) are
> nicely addressed by your recent wake patch [1] (ported to -rc3). Thus
> I see no 'missed IRQ' kernel messages.
> 
> As this addresses a significant usability regression, are you happy to
> add it to the 3.0-rc queue? I think it has very good value in -stable
> also (assuming correctness). What do you think?

This one had significant performance impacts, and later hacks in this
series worked around the problem to approximately the same level of
success with less impact, and we don't actually have a justification of
why any of them work.  We were still hoping to come up with some clue,
and haven't yet.
diff mbox

Patch

diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.c
b/drivers/gpu/drm/i915/intel_ringbuffer.c
index 95c4b14..d3ef07f 100644
--- a/drivers/gpu/drm/i915/intel_ringbuffer.c
+++ b/drivers/gpu/drm/i915/intel_ringbuffer.c
@@ -631,9 +631,11 @@  gen6_ring_get_irq(struct intel_ring_buffer *ring,
u32 gflag, u32 rflag)

 	spin_lock(&ring->irq_lock);
 	if (ring->irq_refcount++ == 0) {
+		gen6_gt_force_wake_get(dev_priv);
 		ring->irq_mask &= ~rflag;
 		I915_WRITE_IMR(ring, ring->irq_mask);
 		ironlake_enable_irq(dev_priv, gflag);
+		gen6_gt_force_wake_put(dev_priv);
 	}
 	spin_unlock(&ring->irq_lock);